Intelligent ∙ Faithful ∙ Honorable
Benedick is motivated by being an aristocratic soldier and fighting for Don Pedro. He is a friend of Don Pedro and Claudio. Not only that, but he also does it for Beatrice. In the beginning of the play, he swears that he will never fall in love, or get married, eventually he does, and pretty much does it for her as well. I believe that's what he is motivated by.